Systems and methods for tracking motion of a bicycle or other vehicles

Abstract

A vehicle tracking system, in various embodiments, is configured to measure vehicle speed, heading, distance travelled, acceleration, and other motion related measurements based at least in part on magnetic field measurements taken by one or more magnetometers. In a particular embodiment, the system comprises one or more magnetometers (e.g., that may be embedded in one or more wearable devices, such as eyewear) and at least one magnet disposed on a portion of the vehicle such as the vehicle's wheel. The system is configured to receive magnetic field information associated with the at least one magnet using the one or more magnetometers and determine the speed and other data based at least in part on the magnetic field information. In various embodiments, the system is configured to track movement and speed of a bicycle.

What is claimed is: 
     
         1 . A computer-implemented method of determining vehicle motion, the method comprising:
 determining, by a processor, using one or more magnetometers, magnetic field information for a first magnet mounted on a wheel of a vehicle at a particular time;   determining, by a processor, based at least in part on the magnetic field information, an angular velocity of the vehicle wheel at the particular time;   determining, by a processor, based at least in part on the angular velocity, a speed of the vehicle at the particular time; and   reporting the speed of the vehicle to a user of the vehicle.   
     
     
         2 . The computer-implemented method of  claim 1 , wherein:
 determining the magnetic field information for the first magnet comprises:
 receiving, at a first time, a first magnetic field measurement from the one or more magnetometers; and 
 receiving, at a second time, a second magnetic field measurement from the one or more magnetometers; and 
   determining the angular velocity of the wheel based at least in part on the magnetic field information comprises:
 determining a time difference between the first time and the second time; and 
 determining the angular velocity based at least in part on the first magnetic field measurement, the second magnetic field measurement, and the time difference. 
   
     
     
         3 . The computer-implemented method of  claim 2 , wherein determining the angular velocity based at least in part on the first magnetic field measurement, the second magnetic field measurement, and the time difference comprises:
 determining a first wheel angle of rotation based at least in part on the first magnetic field measurement; and   determining a second wheel angle of rotation based at least in part on the second magnetic field measurement.   
     
     
         4 . The computer-implemented method of  claim 3 , wherein determining the angular velocity based at least in part on the first magnetic field measurement, the second magnetic field measurement, and the time difference comprises determining an angular difference between the first angle of rotation and the second angle of rotation. 
     
     
         5 . The computer-implemented method of  claim 4 , wherein the first magnetic field measurement is a measurement selected from the group consisting of:
 i. a strength of the first magnetic field; and   ii. a direction of the first magnetic field.   
     
     
         6 . The computer-implemented method of  claim 1 , wherein the one or more magnetometers are at least partially embedded in a pair of eyewear. 
     
     
         7 . The computer-implemented method of  claim 6 , wherein the vehicle is a bicycle. 
     
     
         8 . The computer-implemented method of  claim 1 , the method further comprising:
 determining, by a processor, using one or more magnetometers, a plurality of substantially instantaneous magnetic field information for the first magnet over a particular period of time;   determining, by a processor, based at least in part on the plurality of substantially instantaneous magnetic field information, a plurality of substantially instantaneous angular velocities of the vehicle wheel and a plurality of substantially instantaneous directions of travel of the vehicle over the particular period of time; and   determining, by a processor, based at least in part on the plurality of substantially instantaneous angular velocities, a plurality of substantially instantaneous speeds of the vehicle over the particular period of time.   
     
     
         9 . The computer implemented method of  claim 8 , the method further comprising:
 generating, by a processor, based at least in part on the plurality of substantially instantaneous directions of travel and the plurality of substantially instantaneous speeds of the vehicle, a visual representation of a path travelled by the vehicle during the particular period of time; and   displaying, by a processor, the visual representation of the path to the user.   
     
     
         10 . A computer system for determining and tracking bicycle movement data comprising:
 at least one processor; and   at least one magnetometer, wherein the computer system is configured for:
 receiving, from the at least one magnetometer at a first time, a first magnetic field measurement for a first magnet disposed on a portion of a bicycle selected from the group consisting of:
 a wheel of the bicycle; and 
 a portion of a pedal of the bicycle; 
 
 receiving, from the at least one magnetometer at a second time, a second magnetic field measurement for the first magnet; 
 determining, based at least in part on the first magnetic field measurement and the second magnetic field measurement, a velocity of the bicycle; and 
 storing the velocity of the bicycle in at least one data store. 
   
     
     
         11 . The computer system of  claim 10 , wherein the computer system is further configured for:
 determining a velocity of the bicycle over a particular period of time; and   determining, based at least in part on the velocity of the bicycle over the particular period of time, a distance travelled by the bicycle over the particular period of time.   
     
     
         12 . The computer system of  claim 10 , wherein the computer system is further configured for:
 determining based at least in part on the first magnetic field measurement, a first heading of the bicycle at the first time;   determining based at least in part on the second magnetic field measurement, a second heading of the bicycle at the second time;   storing the first heading and the second heading in at least one data store.   
     
     
         13 . The computer-system of  claim 12 , wherein the computer system is further configured for:
 determining a starting location of the bicycle at the first time; and   determining an ending location of the bicycle at the second time based at least in part on, the starting location, the first heading, the second heading, and the velocity of the bicycle.   
     
     
         14 . The computer system of  claim 10 , wherein the computer system is further configured for:
 receiving, from the at least one magnetometer at a third time, a third magnetic field measurement for the first magnet; and   determining, based at least in part on the first magnetic field measurement, the second magnetic field measurement, and the third magnetic field measurement, a change in velocity of the bicycle.   
     
     
         15 . The computer system of  claim 14 , wherein:
 the first magnet is disposed on the wheel of the vehicle;   a second magnet is disposed on the portion of the pedal of the vehicle; and   the computer system is further configured for:
 receiving, from the at least one magnetometer at the first time, a fourth magnetic field measurement for the second magnet: 
 receiving, from the at least one magnetometer at the second time, a fifth magnetic field measurement for the second magnet; 
 determining, based at least in part on the fourth magnetic field measurement and the fifth magnetic field measurement, an angular velocity of the pedal; 
 determining, based at least in part on the change in velocity of the bicycle and the angular velocity of the pedal, a correlation between the change in velocity of the bicycle and the angular velocity of the pedal; and 
 providing the determined correlation to a rider of the bicycle. 
   
     
     
         16 . A computer-implemented method of determining instantaneous angular velocity of a wheel of a vehicle, the method comprising:
 receiving, by a processor, from one or more magnetometers, a plurality of magnetic field measurements for a first magnet mounted on the wheel over a particular period of time; and   determining, by a processor, based at least in part on the plurality of magnetic field measurements, an instantaneous angular velocity of the wheel at a particular time during the particular period of time.   
     
     
         17 . The computer-implemented method of  claim 16 , wherein:
 determining the instantaneous angular velocity of the wheel at the particular time comprises determining, by a processor, based at least in part on the plurality of magnetic field measurements, an angle of revolution of the wheel associated with each particular one of the plurality of magnetic field measurements.   
     
     
         18 . The computer-implemented method of  claim 17 , the method further comprising:
 determining, based at least in part on the instantaneous angular velocity of the wheel, an instantaneous velocity of the vehicle.   
     
     
         19 . The computer-implemented method of  claim 18 , the method further comprising:
 determining, by a processor, based at least in part on the plurality of magnetic field measurements, a plurality of instantaneous angular velocities of the wheel over the particular period of time; and   determining, by a processor, based at least in part on the plurality of instantaneous angular velocities of the wheel, a distance travelled by the vehicle during the particular period of time.   
     
     
         20 . The computer-implemented method of  claim 19 , the method further comprising:
 displaying, by a processor, the instantaneous velocity and the distance travelled to a rider of the vehicle.